Since coming out of Helix High, he’s played in stadiums of all sorts. Alex Smith has played in most of the domes, Super and otherwise, and football shrines like Lambeau and Soldier Fields. After various re-namings, his home field is back to being Candlestick, appropriate to its own legend.

Through the years with Alex Smith

2000-01: Led Helix High to back-to-back Division II San Diego Section championships.

2004: As a junior, led Utah to 12-0 season, including Fiesta Bowl win over Oklahoma. Finished fourth in Heisman Trophy voting.

2005: Two weeks before 21st birthday, taken as top overall pick in NFL draft by San Francisco.

2006: After a rookie season in which he played in nine games (seven starts) and threw for only one TD with 11 interceptions, Smith played every snap and had equal number (16) of TDs and INTs.

2007: Injured his shoulder in late September but battled with head coach Mike Nolan over the severity of the injury. Smith wound up playing in seven games before undergoing shoulder surgery.

2008: Failed to win the starting job in the summer, then missed the entire season after he was diagnosed with a broken bone in his shoulder.

2009: Started the final 10 games (5-5 record) and threw 18 TD passes against 12 INTs.

2010: Won the starting job in camp and held it for seven games, but was hurt and missed the next five games. Returned Sunday and had the highest single-game passer rating of his career (130.9).

Only one place, though, does he calls “The Stadium.”

Old habit. Unbreakable habit. It’s a local thing.

The NFL tries to knock the boyhood out of a player _ especially a quarterback taken first overall in the draft by a franchise desperate to find its next Joe Montana or Steve Young _ but some things cannot be erased from the memory. No matter the considerable good and bad that’s since happened on a football field to Smith _ who’ll lead the San Francisco 49ers against the Chargers on Thursday night _ that short ride from the visiting-team’s hotel to Qualcomm Stadium is evocative of a happy youth.

“It’s surreal,” Smith, 26, said Tuesday. “I can definitely, vividly remember playing there in high school, taking the bus there the day of the game, what it was like being in those locker rooms as a high school player and taking the field and playing.”

Though he’s in his sixth year with the Niners, who’ve been playing the Chargers in preseason games in each of the last 23 years, Thursday night marks Smith’s first regular-season game at Qualcomm as San Francisco’s starting quarterback. As it happens, it may be his last year with the 49ers, but that’s another story.

Smith’s story to this point has often brought him back to Qualcomm, where he grew up a San Diego State and Chargers fan, watching Marshall Faulk running for the Aztecs and Stan Humphries passing San Diego to its first (and still only) Super Bowl. Local high school football teams build their whole season toward making it to “The Stadium,” where the Highlanders twice won CIF-championship games with Smith at quarterback.

Before he left the University of Utah, Smith would have left his own imprint in The Stadium’s lore, returning for his junior-game against the Aztecs and throwing five touchdown passes. Hearing mere mention of that performance, though, Smith immediately notes a previous game in Mission Valley that likely wasn’t noted about the Utes’ only Heisman Trophy finalist.

“My junior-year (game) was a little different from my freshman year,” said Smith. “That’s when I broke my redshirt, came out and played the fourth quarter. I threw a touchdown. It was for the wrong team, though, a pick-six. I was a freshman, all over the place. I think I got six snaps and got sacked once.”

That game, alas, might’ve served Smith as better preparation for the pros. After compiling a 25-1 record at Helix and a 21-1 mark as Utah’s starter, Smith hasn’t played on a team that finished with winning record since. You can imagine who’s been the most obvious target of derision.

“I’d be lying if I said there was none,” said Smith, asked about the pressure that came with lofty draft status. “When you’re a No.1 pick, there are a lot of expectations on you when you come into an organization with the quarterback history this organization has had.

“I felt like I had to do it right away as a young player. I hurt myself at times because of that. I forced things, tried to do too much, tried to make too many plays instead of letting the plays come to me. That made matters worse.”

Every year, it’s been Smith and somebody else at quarterback, including the likes of J.T. O’Sullivan and Shaun Hill and now Troy Smith. This season hasn’t been much different , but the timing of the game in San Diego is fortuitous for Smith.

Smith missed all of 2008 with an injury to his right shoulder, but it was a problem with his non-throwing shoulder on Oct. 24 that sent him back to the bench, where he stayed for five starts. He was back in the starting lineup last Sunday , however, and led a 40-point assault on the Seattle Seahawks.

Sticking largely with the short passing game and distributing the ball to backs and receivers alike, Smith completed 17 of 27 passes for 255 yards and three touchdowns.

“I thought he took another step, that’s all,” said head coach Mike Singletary. “I think he played pretty decent in the game, executed, and hopefully he can continue to grow.”

Asked if there was any area of Smith’s game that has improved since he took over as head coach in 2008, Singletary bluntly said, “No.”

Any further growth by Smith may come somewhere other than San Francisco. He’s a pending free agent, and with three weeks remaining in the season, the 49ers can do no better than repeat their 8-8 record of last season.

They can, however, still win the NFC West championship. He’s catching the Chargers in much the same circumstance, a single game out of first place. There’ll be more than the locale, too, that’s extremely familiar to Smith.

“He’s gone through some tough times, and obviously, I’m pulling for him,” said Chargers safety Eric Weddle, a former Utah teammate. “We’re expecting him to play great. Alex is athletic, can scramble around, extend plays. When he gets in a rhythm, he can make any throw and really show what kind of quarterback he was.”